Parallel pivot type speed responsive brake



Aug. 10, 1954 w. PFERD ET AL PARALLEL PIVOT TYPE SPEED RESPONSIVE BRAKE Filed Dec. 8, 1950 FIG. 2

. w. PFERD W 2? R. E. PRESCOTT ATTORNEV Patented Aug. 10, 1954 PARALLEL PIvoT TYPE SPEED RESPONSIVE BRAKE William Pferd, Berkeley Heights, and Robert E. Prescott, Bernardsville, N. J assignors to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application'December 8, 1950; Serial No. 199,792

4 Claims. (01. 188 -184) 1 This invention relates to speed regulatin devices and more particularly to frictionally retarded centrifugal governors for telephone callingdials.

-It is common practice in governors of the above type to employ rotatable weights which are thrown outwardly by centrifugal force into fric tional engagement with a stationary member whereby a retarding force is created in opposition to the force which causes the governor to rotate. In structures of this eneral nature, the rotatable weights are usually restrained in their outward movement by a spring or springs, the tension of which maybe varied to regulate the speed of the governor. The speed of the mechanism will increase with the tension of the spring and will decrease as tension is decreased.

It has beenfound that in governors of the aforementioned type, it is difiic'ult to adjustthe rotatable weights in order to provide a retarding force which is uniform with respect to the action of each weight on the stationary member.

One object of this invention is to provide a balanced centrifugal governor, especially. suitable for use in telephone calling dials, which is of simple and inexpensive construction wherein the speed regulation is improved and the efiect of gravity on the weights is reduced so that it has little or no detrimental effect on the operation of the device and a uniform rotational speed is attained.

In accordance with the general features of this invention, there is provided a stationary cupshaped hOllSll'lg having a substantially cylindrical inner wall. A shaft coaxially disposed with respect to the inner wall is rotatably mounted in the cup member and has fixedly secured thereto a drivebar member having two radially extending arm portions, which are adapted to engage and drive a pair of arcuate shaped Weights. The latter are pivotally mounted on an axially disposed fly-bar member which is rotatably mounted on a lower shoulder portion of the drive-bar. The arcuate weights are provided on their peripheries, adjacent their pivot points, with studs which are adapted to frictionally engage the inner wall of the cup member, and on their inner edges with notches to receive the ends of the drive-bar. A spring extends across the assembly and has its ends positioned in notches in the peripheries of the weights for drawing the weights toward each other to disengage the friction studs from the inner wall of the stationary member.

The invention will be more clearly understood from the following detailed description when read in conjunction with the accompanying drawing, of which: r

Fig. 1 is a top plan view of a device illustrative of this invention in its normal, or at rest, position;

Fig. 2 is a view similar to Fig. 1 and shows the operated position of the device; and

Fig. 3 is a cross-sectional view taken on line 33 of Fig. 1.

Referring now to the drawing, the cup-shaped housing or. casing II], has rotatably journaled therein a shaft i I which is operatively connected to the dial operating mechanism (not shown). Fixedly secured to the upper end of the shaft II is a drive-bar member I2, which is provided with radially extending arms I3 and I 5 and is provided at its lower end with a reduced shoulder portion. Rotatably mounted on the reduced shoulder portion is the fly-bar member I5, which is spaced away from the bottom of the cup memher it by the washer Iii. Pivotally mounted on the ends of the fly-bar I5, by means of studs I1 and I 8, are the arcuate shaped weights I9 and 29. These weights are provided on their inner walls with notched portions 2i and 22 in which the ends of the arms I3 and I4 are seated, as shown in Fig. l. A coil spring 23 extends across the assembly and has its ends in engagement with notches 24 and 25 on the periphery of the wei hts I9 and 2t and serves to restrain the outward movement of the weights due to the centrifugal force exerted thereon and the torque force, applied by means of the drive-bar I2, which has its ends I3 and It in engagement with the notches 2i and 22 in the weights I9 audit. The peripheries of the weights It and 29 are provided with studs'ZIS and 2?, which, as shown in Fig. 2,

are adapted to engage the inner wall of the cupshaped member I6, due to the centrifugal and torque forces when the governor is operated to control the rotation of the shaft II.

In the operation of the governor of this invention, the driving torque from the shaft I I, is transmitted to the weights I9 and 2E! through the arms I3 and IQ of the drive-bar I2, which as shown, is secured to the shaft I I, and the fly-bar member I5 and the weights I9 and 20 are free to pivot about the shaft I I.

The governor weights I9 and 26 are caused to rotate by the driving torque of the shaft I I acting on drive-bar I2 thence to the weights I9 and 25 and not through the pivots H and It. With the structure of this invention, the driving torque increases the speed of rotation uniformly until a critical velocity is reached. When speeds in excess of the critical velocity occur, the centrifugal force of the weights l9 and 20 and the force exerted by the arms 13 and 14 of the drivebar 12 on the weights [9 and 20, result in the tuds 25 and 21 frictionally engaging the inner wall of the cup member [0, as shown in Fig. 2.

t is thus readily apparent that both of these forces contribute, during the run-down of the shaft H which is connected to the dial mechanism, not shown, at which time the governor mechanism rotates in a clockwise direction. As the governor assembly rotates, the weights l9 and 2E! tend to move outward under the influence of centrifugal force and torque. The centrifugal force acts through the center of gravity of the weights is and 20 radially from the turning center of the shaft II. The torque force is applied on the weights by the drive-bar arms l3 and 14-. Both of these forces are opposed by the force of the spring 23. The force of the studs 26 and 2'! on the inner wall of the cup member H] results in a frictional component which acts on the weights l9 and 20 to govern the speed regulation of the mechanism secured to the shaft While I have shown and described a preferred embodiment of my invention, it is understood that various changes and modifications may be made therein without departing from the scope and spirit of the invention.

What is claimed is:

1. A centrifugal governor comprising a stationary cup-shaped member, a shaft rotatably journaled therein, a drive-bar member secured to said shaft, a fly-bar member rotatably mounted on the lower end of said drive-bar member, a pair of weights pivotally mounted on the ends of said fly-bar member, said weights each having a notched inner edge and a cam surface adjacent thereto, friction means on each of said weights and extending beyond the outer surface thereof for frictionally engaging the inner wall of said cup member, in response to torque and centrifugal force, said drive-bar member having its end portions in engagement with the notches on the inner edges of said weights, and spring means extending across said weights and secured thereto for drawing them toward each other to disengage V the frictional means from the stationary member.

2. A centrifugal governor comprising a stationary cup-shaped member, a shaft rotatably journaled therein, a drive-bar member secured to said shaft, a fly-bar member rotatably mounted on the lower end of said drive-bar member, a pair of arcuately shaped weights pivotally mounted on the ends of said fly-bar member, said weights each having a notched inner edge and a cam surface adjacent thereto, friction means on each of said weights and extending beyond the outer surface thereof for frictionally engaging the inner wall of said cup member, in response to torque and centrifugal force, said drive-bar member having its end portions in engagement with the notches on the inner edges of said weights, and spring means extending across said weights and secured thereto for drawing them toward each other to disengage the frictional means from the stationary member.

3. A centrifugal governor comprising a sta tionary cup-shaped member, an axial shaft rotatably journaled therein, a drive-bar member, having radially projecting arms, secured to said shaft, a fiy-bar member rotatably mounted on the lower end of said drive-bar member, a pair of weights pivotally mounted on the ends of said fly-bar member, said weights each having a notched inner edge and a cam surface adjacent thereto, friction means on each of said weights and extending beyond the outer surface thereof for frictionally engaging the inner wall of said cup member, in response to torque and centrifugal force, said drive-bar member having the ends of its arms in engagement with the notches on the inner edges of said weights, and spring means extending across said weights and secured thereto for drawing them toward each other to dis engage the frictional means from the stationary member.

4,. A centrifugal governor comprising a stationary cup-shaped member, an axial shaft rotatably journaled therein, a drive-bar member secured to said shaft, a fly-bar member rotatably mounted on the lower end of said drive-bar member, a pair of pivot pins secured on each end of said fly-bar member, weights pivotally mounted on said pins, said weights each having a notched inner edge and a cam surface adjacent thereto, friction means on each of said weights and extending beyond the outer surface thereof for frictionally engaging the inner wall of said cup member, in response to torque and centrifugal force, said drive-bar member having its end portions in engagement with the notches on the inner edges of said weights, and spring means extending across said weights and secured thereto for drawing them toward each other to disengage the frictional means from the stationary member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,206,936 Staude Dec. 5, 1916 1,283,863 Moore Nov. 5, 1918 

